JP2002263439A - Deodorizing method and deodorizing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for efficiently deodorizing a malodorous gas containing hydrogen sulfide generated from various facilities such as sewage treating facilities and to provide a deodorizing apparatus having such a function. SOLUTION: This deodorizing apparatus comprises a biological treating part and an ozonizing part provided with an ozone deodorization catalyst. In the concrete, hydrogen sulfide contained in the malodorous gas as the main component is removed by introducing the malodorous gas from the top of the biological treating part to pass through the biological treating part in a descending current when the malodorous gas is treated by a biological treating method. As a result, only a microbe adequate to remove hydrogen sulfide propagates itself so that hydrogen sulfide can efficiently be removed and excellent hydrogen sulfide removing performance can be obtained even when the equipment is compact. The remaining malodorous component is removed by bringing the malodorous gas from which hydrogen sulfide is removed in the biological treating part into contact with the ozone deodorization catalyst in the presence of ozone in the ozonizing part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deodorizing method and a deodorizing apparatus capable of efficiently removing an unpleasant odor component mainly composed of hydrogen sulfide generated from a sewage treatment facility or a food treatment facility. .

[0002]

2. Description of the Related Art In recent years, with the rapid artificial increase, the urban area has expanded to the vicinity of a sewage treatment facility due to land conditions and the like, and it is required to improve the environment near the sewage treatment facility. In particular, odorous gas generated from sewage treatment facilities contains sulfur-based odor components such as hydrogen sulfide, methyl mercaptan, methyl sulfide, and methyl disulfide. With the rise of odors, countermeasures against odors generated from sewage treatment facilities have become a major issue.

[0003] As a method for deodorizing such an odor, for example, an adsorption method using an adsorbent such as activated carbon has been proposed. However, in the deodorizing method using an adsorbent, there is a limit to the amount of adsorbed adsorbent, and when the adsorbing performance reaches saturation, it is necessary to replace the adsorbent, which requires complicated maintenance work. Especially when the concentration of odorous components in the sludge treatment equipment at the sewage treatment plant is high, the adsorbent breaks down early and the performance decreases, so it is necessary to replace the adsorbent frequently and the running cost increases. Had the problem of doing so.

A chemical cleaning method using a chemical has also been proposed. However, even in this method, when the odor component concentration is high, a large amount of the chemical is required, the running cost is high, and the used chemical after the cleaning is treated as a waste liquid. Have to do
There were problems such as an increase in processing equipment.

Further, a biological treatment method using microorganisms has been proposed. However, when the types of microorganisms that act depend on the odor components to be treated, and when various types of odor components are mixed, it is necessary for each microorganism to propagate. It was necessary to prepare a suitable environment. Therefore, in order to deodorize complex odors by the biological treatment method, the inside of the biological treatment device is divided vertically or horizontally to arrange the microbial carriers in a multi-stage manner, and to control the washing and pH of the products in each stage. For this reason, the apparatus has been complicated, such as adjusting the water supply amount for each stage, or separately treating drain water. However,
Even with such a complicated biological treatment device, the odor gas generated from the sewage treatment plant contains odor components that are difficult to be treated by microorganisms, such as methyl sulfide and methyl disulfide, so that a sufficient deodorizing effect can be obtained. Could not be obtained. Therefore, in order to remove such odorous components that are difficult to be biologically treated, an adsorbent such as activated carbon must be provided as a post-treatment, which causes a problem that the equipment becomes larger and the maintenance and management of the equipment becomes complicated. Had.

As a method for solving such a problem, a deodorizing method using a catalyst has recently been proposed. For example, there has been proposed an ozone deodorizing catalyst method for deodorizing odor components at room temperature by utilizing the oxidizing power of ozone. However, the performance of the ozone deodorizing catalyst deteriorates rapidly when it is poisoned by hydrogen sulfide, so it is difficult to apply it to facilities that may generate high concentrations of odorous gas containing hydrogen sulfide, such as sewage treatment facilities. Was.

As a method for preventing such deterioration of the ozone deodorizing catalyst, for example, Japanese Patent Application Laid-Open No. 6-254347 discloses a method in which hydrogen sulfide is removed as a pretreatment by a liquid catalyst comprising a naphthoquinone derivative or a naphthohydroquinone derivative and then ozone is removed. A method of treating with a deodorizing catalyst has been proposed. The pretreatment method can remove hydrogen sulfide as sulfur by the action of a liquid catalyst without consuming a chemical or the like. However, since the generated sulfur is accumulated in the liquid as a solid content, when the concentration of hydrogen sulfide is high, there is a problem that the solid concentration rapidly increases. Therefore, it is necessary to increase the capacity of the circulating liquid storage tank or to periodically filter out solids in the liquid using a filter or the like.

Japanese Patent Application Laid-Open No. 8-71361 proposes a method of pretreating hydrogen sulfide using a solid desulfurizing agent such as a metal oxide. However, even if a pretreatment using a solid desulfurizing agent is performed, the desulfurizing agent must be frequently replaced when a high concentration of hydrogen sulfide is treated.

That is, the above-mentioned method using a liquid catalyst or a solid desulfurizing agent exhibits an excellent effect when the concentration of hydrogen sulfide such as odor gas generated from a water treatment facility of a sewage treatment facility is relatively low, and is efficient. However, it is not an optimal method for treating odorous gas containing a high concentration of hydrogen sulfide generated from a sludge treatment facility or the like.

As described above, various deodorizing methods such as an adsorption method, a chemical cleaning method, a biological treatment method, and a catalytic method have been proposed as odor treatment methods in a sewage treatment facility. Since a sufficient deodorizing effect cannot be obtained for odorous gas containing odorous components, development of a deodorizing technique capable of solving such a problem has been desired.

[0011]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to include a high concentration of hydrogen sulfide of 10 ppm or more generated from various facilities such as a sewage treatment facility. The purpose of the present invention is to provide a method for efficiently deodorizing odorous gas, and in particular, to maintain excellent processing performance over a long period of time even with compact processing equipment, and to have good economical efficiency such as running cost. It is another object of the present invention to provide a deodorizing method that facilitates maintenance of the apparatus and a deodorizing apparatus having such a function.

[0012]

According to the study of the present inventors, it has been found that the above object can be achieved by the following invention. (A) A deodorizing method characterized in that, when an odor gas containing hydrogen sulfide is treated and deodorized by a biological treatment method, the odor gas is introduced from the upper part of the biological treatment part and aerated in a downward flow. (B) In treating and deodorizing odorous gas containing hydrogen sulfide, the odorous gas is introduced from the upper part of the biological treatment section and aerated in a downward flow to remove hydrogen sulfide by a biological treatment method. A deodorizing method characterized by contacting the ozone with an ozone deodorizing catalyst in the presence of ozone. (C) A deodorizing apparatus for treating odorous gas containing hydrogen sulfide, which is a packed tower type biological treatment section for removing hydrogen sulfide by a biological treatment method, and for removing remaining odor components by an ozone deodorizing catalyst method. A deodorizing device comprising: an ozone treatment section.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The method of the present invention which has attained the above-mentioned object is to treat an odor gas containing hydrogen sulfide as a main component in a packed tower type biological treatment method. This is a deodorization method whose main purpose is to remove hydrogen sulfide more efficiently by introducing microorganisms and passing the gas through a downflow.

The principle of biological treatment is to convert odor components into odorless substances by biochemical reactions of microorganisms. Hydrogen sulfide is oxidized by sulfur-oxidizing bacteria to produce sulfuric acid. By using the method of the present invention, a high concentration of hydrogen sulfide can be removed by the action of microorganisms without using consumables such as drugs, oxidizing agents, and adsorbents. The running cost can be significantly reduced as compared with the conventional method.

[0015] A main product of the biological treatment section when treating an odor gas containing hydrogen sulfide as a main component is sulfuric acid. Since the sulfuric acid is a strong acid, the biological treatment section exhibits an acidity, and particularly, the inlet section having a high concentration of hydrogen sulfide tends to be acidic. Watering is performed from the upper part of the biological treatment section, and the generated sulfuric acid flows down by watering. In the present invention, since the odor gas is also introduced from the upper part of the biological treatment part, both the gas and liquid flow downward, and the sulfuric acid generated at the upper part moves to the lower part, so that the whole biological treatment part tends to be acidic. This makes it easier for the biological treatment section to propagate only microorganisms suitable for removing hydrogen sulfide. That is, by using the biological treatment section having the above configuration, excellent hydrogen sulfide removal performance can be obtained with compact equipment.

Water is continuously or intermittently sprinkled from the upper part of the biological treatment part in order to replenish the water necessary for the inhabitation of microorganisms.
It is recommended to control the amount of water spray so that H is 2-3. This makes it possible to prepare an optimum growth environment for microorganisms suitable for removing hydrogen sulfide.

As a further preferred embodiment of the present invention, a deodorizing method for removing residual odor components efficiently by removing hydrogen sulfide as a main component in the biological treatment section and then contacting it with an ozone deodorizing catalyst in the presence of ozone. Is mentioned. The biological treatment unit removes hydrogen sulfide, which is easy to treat with microorganisms, and treats methyl sulfide and methyl disulfide, which are difficult to treat with microorganisms, by the ozone deodorization catalyst method, achieving compactness of the entire system and improving treatment efficiency. it can.

The deodorizing device according to the present invention is a deodorizing device for treating odorous gas containing hydrogen sulfide, and is provided with a biological treatment section which ventilates in a downflow at a preceding stage to remove hydrogen sulfide.
This is a deodorizing apparatus having a gist in that an ozone treatment unit having an ozone deodorizing catalyst is provided at a later stage.

According to the present invention, when an odor gas containing hydrogen sulfide as a main component is treated by a biological treatment method, typically a packed tower type biological treatment method, the odor gas is introduced from the upper part of the biological treatment part and lowered. It is characterized by being ventilated by flow. The deodorizing method of the present invention can be an effective deodorizing method by applying it when the odor gas to be treated mainly contains hydrogen sulfide. In particular, it is suitable for treating odorous gas in which the concentration of hydrogen sulfide generated from a sludge facility of a sewage treatment facility becomes 10 ppm or more. The present invention, as described above,
When treating odorous gas containing hydrogen sulfide as a main component using a biological treatment method, typically a packed tower type biological treatment method, microorganisms suitable for removing hydrogen sulfide as a main component of odor gas This is a deodorizing method for the purpose of treating efficiently by preparing the growth environment of the plant. The biological treatment section is of a packed tower type in which microorganisms are held on a carrier, and as the carrier, known ones such as granules and aggregates, plate-like bodies, fiber aggregates, laminates, and sponge bodies can be used. For example, Lahisiling or Terra Red molded from synthetic resin such as polypropylene, or porous ceramics such as silica,
Examples include peat, zeolite, charcoal, activated carbon, wood chips, foams (sponge-like), and the like. Although not particularly limited, it is preferable that the material is porous, has a large contact surface area, has good water retention and acid resistance, is lightweight, has good air permeability, and is a high-strength material. The size and shape of the carrier are not particularly limited, either.
It can be appropriately changed in consideration of various factors such as a processing gas amount, a processing gas concentration, and an installation area.

A method for retaining microorganisms on a carrier is, for example, removal of hydrogen sulfide contained in the odor gas by attaching activated sludge used for sewage treatment, urine and urine treatment, etc., to the carrier and contacting it with an odor gas. Suitable microorganisms can propagate and be immobilized on the carrier. Immediately after the operation of the deodorizing device, the growth of microorganisms is insufficient. However, by providing a habituation period of about 1 to 3 weeks, predetermined performance can be obtained. To compensate for the initial performance shortage, it is recommended to use a highly adsorbent material such as activated carbon or zeolite as a carrier for holding microorganisms, and activated carbon is an excellent treatment for hydrogen sulfide, which is a main component of odor gas. It is preferable because it has the ability.

In order to stably exhibit the treatment of microorganisms, it is necessary to prepare an environment suitable for growing microorganisms by continuously or intermittently supplying water to the carrier on which the microorganisms are immobilized. Watering is necessary for the growth of microorganisms. When watering is performed intermittently, the amount of watering is adjusted to prevent the carrier from drying. In addition, products or dead bodies of microorganisms can be discharged by watering. As the water for sprinkling, for example, tap water or treated water of a sewage treatment facility can be used. The watering method is not particularly limited, but it is desirable to uniformly supply the water to the carrier, so that it is recommended to spray water in a shower shape.

The water spray can be of a one-time type or a circulation type, but it is preferable that the drain water flowing down the biological treatment part be acidic because of sulfuric acid generated by microorganisms. In particular, in a sewage treatment facility, since there is a wastewater treatment facility, drain water can be returned to the facility, and no additional equipment such as pH adjustment of the drain water is required, so that the deodorizing device can be simplified. Further, the wastewater may be neutralized by adding an alkali and then discharged, or may be reused as water for sprinkling.

[0023] Hydrogen sulfide, which is the main component of the odor gas of the present invention, is oxidized by sulfur-oxidizing bacteria to sulfuric acid. Sulfuric acid is a strong acid, so the carrier on which the microorganisms are held becomes acidic.However, ordinary microorganisms cannot be activated unless the pH is neutral. Without proper preparation, biological treatment cannot be applied. Therefore, conventionally, when an odor gas containing hydrogen sulfide as a main component is treated by a packed tower type biological treatment method, it is general to ventilate the gas as an upward flow from the lower part of the biological treatment part. In this method, sulfuric acid is generated at the lower portion of the biological treatment section, and the generated sulfuric acid can be washed away by water sprinkling from the upper portion. As a result, the upper part of the biological treatment section can maintain the pH at neutral, and microorganisms suitable for removing odor components other than hydrogen sulfide such as methyl mercaptan, methyl sulfide, and methyl disulfide can be inhabited. However, in order to remove high-concentration hydrogen sulfide and methyl sulfide which are hardly treated by microorganisms, a sufficient deodorizing effect cannot be obtained unless the contact time of the biological treatment section is considerably long. In addition, in the gas rising flow, the entrance where the microorganisms proliferate due to contact with the high concentration of hydrogen sulfide is located at the bottom of the biological treatment part, so that the microorganisms easily flow out by watering and it is difficult to effectively use the biological treatment part.

On the other hand, the odor gas to be treated in the present invention is introduced from the upper part of the biological treatment part, and sulfur oxidizing bacteria suitable for removing high-concentration hydrogen sulfide are propagated at the entrance of the biological treatment part. I do. As a result, a large amount of sulfuric acid is generated in the upper part, and the generated sulfuric acid flows out to the lower part by water sprinkling. Therefore, if the operation is continued using the deodorizing method of the present invention, the entire biological treatment part becomes acidic. It is known that some bacteria of the genus Thiopacillus, which is a sulfur oxidizing bacterium of hydrogen sulfide, are acidic and can be actively activated, and only the microorganisms that remove hydrogen sulfide grow when the entire biological treatment section becomes acidic. become. In addition, surplus microorganisms flow from the carrier by water sprinkling, but can adhere to the lower carrier and distribute the microorganisms throughout the biological treatment section. Accordingly, even if, for example, a high concentration of hydrogen sulfide flows in temporarily, the number of microorganisms retained is large, so that it is possible to cope with gas concentration fluctuations. However, the conventional ascending flow cannot cope with a temporarily high-concentration gas because microorganisms propagate in accordance with the normal concentration of hydrogen sulfide. By making the gas flow downward, the biological treatment section, which is the object of the present invention, can be set in an environment optimal for removing hydrogen sulfide, and hydrogen sulfide can be treated efficiently.

The contact time of the biological treatment section is not particularly limited, but is preferably 2 seconds or more, more preferably 3 seconds or more, and is preferably 12 seconds or less, more preferably 8 seconds or less. If the contact time is less than 2 seconds, hydrogen sulfide may not be sufficiently removed to a target concentration. If the contact time exceeds 12 seconds, the size of the apparatus is increased and the cost is increased.

Further, it is desirable to adjust the amount of watering in order to control the environment suitable for the growth of microorganisms, and to determine the optimum amount of watering per hour according to the odor conditions to be treated and the water retention of the carrier used. do it. At this time, it is desirable to measure the pH of the drain water in the biological treatment section and adjust the amount of water sprayed so as to obtain a desired pH. As described above, the present invention is characterized in that the biological treatment section is kept acidic to provide an environment suitable for removing hydrogen sulfide, and the pH of the drain water is preferably in an acidic range, more preferably the pH of the drain water. It is preferable to adjust the amount of watering so that the water content is 2 to 3.

By maintaining the pH of the drain water in an acidic range, the growth of bacteria acting on odor components other than hydrogen sulfide is remarkably suppressed, and sulfur of the genus Thiopatilus which can live in an acidic range in which removal of hydrogen sulfide is oxidized to sulfuric acid. Only oxidizing bacteria can propagate in the biological treatment section. If the pH of the drain water is outside the above range, the activity of microorganisms suitable for removing hydrogen sulfide becomes inactive, which is not preferable.

In a conventional biological treatment method, in a method in which the biological treatment section is a multi-stage system having two or more stages, it is possible to apply a downward flow as disclosed in the present invention to the first stage. Thereby, hydrogen sulfide can be efficiently removed as in the present invention. However, in the biological treatment section in the second and subsequent stages, it is configured to remove methyl sulfide and methyl disulfide, which are difficult to treat with microorganisms. As a result, the load in the biological treatment section in the second and subsequent stages increases, so the biological treatment section Could not be made more compact.

The deodorizing method disclosed in the present invention makes it possible to remove hydrogen sulfide, which is a main component of odorous gas, with high efficiency. In addition, by maintaining the biological treatment section in an acidic region, the generated sulfuric acid can simultaneously remove a basic gas such as ammonia or trimethylamine.
When the treatment performance is insufficient with the above biological treatment alone, it can be combined with other deodorizing techniques. Since high-concentration hydrogen sulfide, which is a main component, has been removed by biological treatment, various treatment techniques can be applied after biological treatment.

As a deodorizing method of a preferred embodiment of the present invention,
After efficiently removing hydrogen sulfide by the biological treatment method in the biological treatment section, the treatment gas is further contacted with an ozone deodorization catalyst in the presence of ozone to remove remaining odor components by the ozone deodorization catalyst method and deodorize. Method. In other words, hydrogen sulfide, which is a main component of odorous gas and easily removed by microorganisms, is efficiently removed by a compact biological treatment unit,
This is an optimal combination for removing the remaining odor components such as methyl sulfide in the ozone treatment section, which are difficult to remove by biological treatment but can be easily treated by the ozone deodorizing catalyst.

The ozone treatment in the present invention means that active oxygen is generated on the surface of the catalyst by bringing an odor component into contact with an ozone deodorizing catalyst in the presence of ozone, and the active oxygen and the odor component are reacted to deodorize. Processing.

The type of the ozone deodorizing catalyst is not particularly limited.
Mn, Fe, Ni, Cr, Co, Ag, Ti, Si, Z
Those containing at least one metal oxide selected from r and Cu and those containing at least one selected from platinum group metals such as Pt, Pd and Rh can be used. For example, catalysts disclosed in JP-A-63-182032 and JP-A-63-267440 are exemplified.

The shape of the ozone deodorizing catalyst is not particularly limited, but a honeycomb-shaped catalyst having a large geometric surface area is desirable.
It is recommended to use a catalyst having a cell number on the order of 0 cells / inch ² .

In order to remove odor components with an ozone deodorizing catalyst, a necessary amount of ozone must be supplied.
The supply amount can be appropriately determined based on various factors such as processing conditions. Usually, odor can be deodorized by adding 1 to 5 mol of ozone to 1 mol of the odor component. For example, the odor generated from the sludge treatment facility of the sewage treatment facility is 30 ppm of hydrogen sulfide, 3 ppm of methyl mercaptan, 0.4 ppm of methyl sulfide, and 0.1 ppm of methyl disulfide.
It contains 4 ppm and 2 ppm of ammonia, and if there is no biological treatment part, a sufficient deodorizing effect cannot be obtained unless ozone is added at 100 ppm or more. However, by adding the biological treatment part of the present invention, the ozone addition amount can be reduced. 1/5 to 1
/ 20.

The contact time between the ozone deodorizing catalyst and the odor gas is not particularly limited, but is preferably set to 0.3 seconds or more. If the contact time is less than 0.3 seconds, it is difficult to obtain a sufficient removal effect. The upper limit of the contact time is not particularly limited, but is preferably 3 seconds, more preferably 1 second, since a sufficient removal effect can be obtained with a contact time of about 3 seconds.

When an ozone deodorizing catalyst is used, 99% of odor components such as methyl sulfide and methyl disulfide which are difficult to be removed by a chemical cleaning method or a biological treatment method are obtained in a contact time of 1 second or less.
Since a high removal rate as described above can be obtained, stable processing performance can be maintained for a long time in a compact apparatus. The ozone deodorizing catalyst also has an ozonolysis function, and does not discharge harmful ozone outside the apparatus.

The method of the present invention can be suitably used for deodorizing odorous gas generated from a sewage treatment facility or the like.
In particular, high concentration generated from sludge treatment equipment, for example, 1
It exerts an excellent effect on odorous gas containing about 0 to 50 ppm of hydrogen sulfide.

According to the deodorizing method of the present invention, high-concentration hydrogen sulfide contained in odorous gas can be removed in the biological treatment section without using consumables such as ozone, chemicals, desulfurizing agents and activated carbon. It is more economical than the prior art using consumables. Further, the biological treatment section can be set as a growth environment of microorganisms suitable for removing hydrogen sulfide, and hydrogen sulfide can be efficiently removed by biological treatment. In addition, since methyl sulfide and the like that are difficult to remove by biological treatment are removed in the ozone treatment section at the subsequent stage, a very compact apparatus can be designed. Furthermore, since hydrogen sulfide, which is a catalyst poisoning substance, is removed in the biological treatment section, the service life of the ozone deodorizing catalyst becomes longer, and the economic efficiency and maintenance and management can be greatly improved.

Hereinafter, the deodorizing apparatus of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic diagram showing one configuration example of the deodorizing device used in the present invention, but the device used in the present invention is not limited to this.

In the deodorizing apparatus according to the present invention, the odor gas to be treated is introduced from above into the biological treatment section 1 filled with the carrier 5 for holding microorganisms, and the biological treatment section is ventilated in a descending flow, whereby the odor is removed. This is a deodorizing apparatus having the gist of having an ozone treatment unit 10 which removes hydrogen sulfide which is a main component of and then makes contact with an ozone deodorizing catalyst 15 to deodorize.

As shown in FIG. 1, the water supply mechanism 4 is provided above the biological treatment section. The water supplied from the sprinkling supply mechanism 4 is showered on the microorganism carrier 5,
Further, it flows down toward the lower part of the biological treatment section 1. At this time, the structure is such that water supplied from the sprinkling supply mechanism 4 and drain water containing components and products decomposed by microorganisms accumulate in the bottom portion 6 of the treatment section and are discharged from the drain outlet 15 through a U-shaped pipe. Has become.

The ozone treatment section 10 is an ozone deodorizing catalyst 1
5 is a mechanism. The ozone deodorizing catalyst 15 generates active oxygen on the surface of the catalyst by contacting with ozone, and has an action of deodorizing odor components by the active oxygen. Before entering the ozone treatment section, ozone is added to the odor gas by the ozone supply mechanism 8. Such an ozone supply mechanism 8 has an ozone generation means such as an ozone generator, a control means for controlling the amount of generated ozone, and a means for enabling a desired ozone supply such as a supply amount control valve. In FIG. 1, the ozone supply mechanism 5 is installed between the biological processing unit 1 and the ozone processing unit 10, but may be installed in the ozone processing unit 10. It is preferable to add ozone to the odor gas by the ozone supply mechanism 8 and then pass through the blower 13 so that the odor gas and ozone can be uniformly mixed. Regarding the ozone treatment unit 10, there is no restriction on the directionality of the odor gas, and either the upward flow or the downward flow may be used. However, the odor gas after the biological treatment has a high humidity and the ozone deodorizing catalyst 15 is condensed and gets wet. Therefore, it is recommended that an odor gas is introduced from the lower part of the ozone treatment unit, and the mist removal unit 7 is installed in front of the ozone deodorization catalyst 15.

When the odor gas containing hydrogen sulfide is treated by the apparatus having the above-described configuration, the odor gas is introduced from the biological treatment section gas inlet 2 provided at the upper part of the biological treatment section 1. Then, when the odor gas passes through the carrier 5 holding the microorganisms filled in the processing section 1 in a downward flow, the hydrogen sulfide is removed by the microorganisms as sulfuric acid. Processing unit 1
Water is showered from the sprinkling supply mechanism 4 provided on the upper part of the biological treatment part to the carrier 5, and the sulfuric acid generated at the upper part of the biological treatment part flows down together with the water, so that the whole biological treatment part comprising the microorganism carrier 5 becomes acidic. Drain water collected at the bottom of the biological treatment section 6
Is discharged from the drain outlet 7. In addition, it is preferable to control the sprinkling amount and the intermittent time of the drain water according to the operating conditions so that the pH is in the range of 2 to 3 using a pH meter or the like.

The odor gas thus treated by the biological treatment unit 1 is discharged from the biological treatment unit gas outlet 3, and the ozone generated by the ozone supply mechanism 8 is added from the ozone supply line 9 and introduced into the ozone treatment unit. It is introduced into the ozone treatment unit 10 through the port 11. The odor gas is sucked by the blower 13, the odor component and ozone are uniformly dispersed, and the odor gas is passed through the mist separator 14 to the ozone deodorizing catalyst 15. The odor component comes into contact with the ozone deodorizing catalyst 15, is decomposed and removed (deodorized), and is discharged from the ozone treatment section discharge port 12.

The odor gas containing hydrogen sulfide generated from a sewage treatment facility or the like can be efficiently deodorized by the method of the present invention.

[0046]

EXAMPLES Hereinafter, the present invention will be described in more detail by way of examples, but the following examples do not limit the present invention.
Modifications and alterations that do not depart from the spirit described below are all included in the technical scope of the present invention. Example 1 A column-shaped reactor was filled with a ring-shaped ceramic carrier inoculated with microorganisms, and a deodorization test of a hydrogen sulfide-containing odor gas was carried out by a packed tower biological treatment method. This odor gas is introduced from the upper part of the biological treatment section, and the gas amount is 1 m ³ / hour,
The superficial velocity was 0.1 m / sec and the contact time was 5 seconds. An odor gas having a hydrogen sulfide concentration of 10 ppm is continuously supplied to the above test apparatus, and water is intermittently sprinkled to drain water.
The amount of water spray was adjusted so that H was 2.5 to 3. The processing performance of hydrogen sulfide gradually improved, and became a stable processing performance in one week, and the hydrogen sulfide removal rate became about 97%. After one month of acclimatization, the inlet gas concentration was changed to examine the effect of the biological treatment on gas concentration fluctuations. Table 1 shows the results of measuring the hydrogen sulfide removal efficiency for each concentration. Comparative Example 1 A hydrogen sulfide deodorizing test was performed in the same manner as in Example 1 except that the odor gas was introduced from the lower part of the biological treatment section. The hydrogen sulfide removal performance gradually improved, and a stable treatment performance was obtained in three weeks, and the hydrogen sulfide removal rate was about 93%. Table 1 shows the results of examining the hydrogen sulfide removal performance by changing the inlet gas concentration after one month of acclimatization treatment in the same manner as in Example 1.

[0047]

[Table 1]

From the above results, it is possible to acclimate microorganisms suitable for removing hydrogen sulfide in a short period of time by introducing gas from the biological treatment section from above to the odor gas containing hydrogen sulfide as shown in Example 1. it can. On the other hand, as compared with Example 1, Comparative Example 1 requires a longer period of time to acclimate the microorganisms, and is presumed to be an effect such as outflow due to watering of the microorganisms. If the acclimatization period of the microorganism is long, the deodorizing effect during the period is insufficient, and the odorous gas is diffused into the atmosphere, which is not preferable.

Further, from the results shown in Table 1, in Example 1, it is hard to be affected by the concentration of hydrogen sulfide at the inlet, and it is possible to treat even if a high concentration of hydrogen sulfide temporarily flows into the deodorizing apparatus. This is presumed to be that in Example 1, the entire biological treatment section can be effectively used and a sufficient number of bacteria is maintained, so that such a change in gas concentration can be dealt with. However, it is considered that the conventional method of introducing the gas of Comparative Example 1 from the bottom did not adequately cope with fluctuations in gas concentration, and the number of bacteria was insufficient for a high concentration load, and a sufficient deodorizing effect could not be obtained. . Example 2 Using the deodorizer shown in FIG. 1, the effect of deodorizing odorous gas containing hydrogen sulfide generated from a sewage treatment plant was examined. The amount of odor gas introduced into the deodorizing device is 20 m ³ / hour, a column-shaped packed tower is used in the biological treatment section 1, and the superficial velocity is 0.
The speed was set to 1 m / sec. The treated water in the aeration tank of the sewage treatment facility was made to adhere to a pellet-shaped carrier 2 made of activated carbon and filled in the biological treatment section 1. At this time, the filling amount of the carrier holding the microorganism was set such that the contact time between the microorganism and the hydrogen sulfide-containing odor gas was 7.5 seconds. A shower type sprinkler was provided above the carrier 2 as the sprinkling supply mechanism 4, and water was intermittently sprinkled, and the sprinkling amount was adjusted so that the pH of the drain water became 2.5 to 3.

Catalyst inlet introduced into ozone deodorizing catalyst 15
Ozone supply mechanism 8 so that the ozone concentration of
The amount of ozone generated supplied was adjusted. Ozone deodorizing catalyst
15 as a binary composite oxide of Ti and Si and a diacid
Uses honeycomb-shaped catalyst composed of manganese oxide
And the contact time with the odor is 1 second (space velocity 3600 hr
^-1) And the ozone deodorizing catalyst 15
10 was filled.

During the test period, the odor gas is continuously supplied without stopping, and the water supplied by the sprinkling supply mechanism 4 is appropriately discharged from the system through a drain port 7 provided at the bottom of the biological treatment section 1. Drained. Table 2 shows the results of the deodorizing performance test at each measurement site three months after the start of the test. Comparative Example 2 As Comparative Example 2, the deodorizing effect was examined in the same manner as in Example 2 using a deodorizing apparatus as shown in FIG. Comparative Example 2 was a biological treatment two-stage system in which the same biological treatment unit used in Example 2 was installed in two towers in series. However, the odor gas is introduced from the lower part of the biological treatment section, and the ventilation direction is ascending in both stages, and the drain water is drained in the second stage so that the pH of the first stage becomes 2.5 to 3. The pH was separately adjusted to be 6.5 to 7. Table 2 shows the performance test results at each measurement site.

[0052]

[Table 2]

From Table 2, it can be seen that Example 2 employing the deodorizing method and apparatus of the present invention has an excellent removal effect on the high-concentration odor generated from the sewage treatment plant, and almost no odor at the outlet of the ozone treatment section. The odor gas concentration is below the detection limit of the analyzer. It also shows excellent deodorizing efficiency at odor concentrations using an olfactory test. The odor concentration is measured using the three-point comparison odor bag method, and is a scale indicating the odor intensity indicating how many times the original odor is diluted to make it odorless. On the other hand, with the biological deodorizing method shown in Comparative Example 2 alone, the odor component remains despite having a sufficient contact time as compared with Example 2, and a satisfactory deodorizing effect could not be obtained. It can be seen that the predetermined deodorizing performance cannot be obtained unless the activated carbon adsorption equipment is added.

[0054]

By employing the deodorizing method and deodorizing apparatus of the present invention, it has become possible to efficiently deodorize odorous gas containing hydrogen sulfide as a main component. In particular, it is possible to design a compact apparatus even for an odor gas containing a high concentration of hydrogen sulfide generated from a sludge treatment facility of a sewage treatment facility. In addition, the responsiveness to gas concentration fluctuation, which is a problem of the conventional biological treatment method, is significantly improved.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing one configuration example of a deodorizing device according to the present invention.

FIG. 2 is a schematic diagram showing one configuration example of a conventional deodorizing device.

[Explanation of symbols]

 1. Biological processing unit 2. Biological treatment section gas inlet 3. Bioprocessing section gas outlet ４. Sprinkling supply mechanism 5. Microbial carrier 6. 6. Drain water Drain outlet 8. Ozone supply mechanism 9. Ozone supply line 10. Ozone treatment unit 11. Ozone treatment unit gas inlet 12. Ozone treatment section gas outlet 13. Blower 14. Mist separator 15. Ozone deodorizing catalyst

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) B01D 53/86 F term (Reference) 4C080 AA07 BB02 CC04 CC14 CC15 HH05 KK08 LL10 MM08 MM33 QQ01 QQ11 4D002 AA03 AA05 AB02 AC10 BA03 BA17 CA07 DA51 DA59 EA05 GA01 GB09 4D048 AA03 AA22 AC07 BA06X BA07X BA28X BA41X BA42X BB02 CD08 CD10

Claims (4)

[Claims] 1. A deodorizing method characterized in that when an odor gas containing hydrogen sulfide is treated by a biological treatment method to deodorize the odor gas, the odor gas is introduced from the upper part of the biological treatment part and aerated in a downward flow. 2. The deodorizing method according to claim 1, wherein the water spray amount is adjusted so that the pH of the drain water in the biological treatment section becomes 2 to 3. 3. In treating and deodorizing an odor gas containing hydrogen sulfide, the odor gas is introduced from the upper part of the biological treatment section and aerated in a downward flow to remove hydrogen sulfide by a biological treatment method. A deodorizing method comprising contacting a treatment gas with an ozone deodorizing catalyst in the presence of ozone. 4. A deodorizing apparatus for treating an odor gas containing hydrogen sulfide, wherein the odor gas is introduced from the upper part of the biological treatment section and aerated in a downward flow to remove hydrogen sulfide by a biological treatment method. A deodorization apparatus comprising: a packed-tower-type biological treatment section of (1); and an ozone treatment section for removing remaining odor components by an ozone deodorization catalyst method.